De or het regiokorting?

The correct Dutch article is:

de regiokorting

Rule Words ending in -ing: almost always de. See the rule

How to use regiokorting

the regiokortingde regiokorting
this regiokortingdeze regiokorting
that regiokortingdie regiokorting
our regiokortingonze regiokorting
your regiokortingjouw regiokorting
every regiokortingelke regiokorting
which regiokorting?welke regiokorting?
a big regiokorting / the big regiokortingeen grote regiokorting, de grote regiokorting